Tepco mistakenly published concealed data of activation product in groundwater

170,000 Bq/m3 of Mn-54 was measured from groundwater taken in Reactor 1 seaside.

This was represented on Tepco’s analysis data published on 11/26/2014.


Tepco didn’t take a sample from this boring since 11/21/2014, so there shouldn’t be the analysis data of “11/24/2014”. However 170 Bq/L of Mn-54 is represented as “the highest reading in the past analysis”. It reads that the sample was taken on 11/24/2014 and it’s written in red letter for some reason.

Exactly, it is represented as “170.00” and the lower part of letters is missing. It can be 170,000 Bq/L.


All the other readings of near area are lower than detectable level. The previous highest reading was 640 Bq/m3 on 2/20/2014.

Mn-54 has a half-life of only 312 days. It’s activation product of Fe-54 and neutron.









Français :

Tepco publie par erreur des données confidentielles sur un produit d’activation dans les eaux souterraines


170 000 Bq/m³ de Mn 54 (manganèse 54) ont été relevés dans les eaux souterraines du côté mer du réacteur 1.
C’est publié dans des résultats d’analyse de Tepco du 26 novembre 2014.

Tepco n’avait pas pris d’échantillon dans ce forage depuis le 21 novembre 2014, ce ne peut donc être un résultat d’analyses du “24 novembre 2014”. Néanmoins, 170 Bq/L de Mn 54 sont présentés comme étant “le record de toutes les analyses précédentes”. On lit que l’échantillon est du 24 novembre 2014 et c’est écrit en rouge.
En fait, il est écrit “170,00” et le bas des lettres n’est pas imprimé. Ce peut être 170 000 Bq/L.

Tous les autres relevés proches de l’endroit sont en dessous du niveau détectable. Le précédent record était de 640 Bq/m³ au 20 février 2014.
Le Mn 54 a une demie-vie de 312 jours seulement. C’est un produit de l’interaction du fer 54 avec un neutron.


About this site

This website updates the latest news about the Fukushima nuclear plant and also archives the past news from 2011. Because it's always updated and added live, articles, categories and the tags are not necessarily fitted in the latest format.
I am the writer of this website. About page remains in 2014. This is because my memory about 311 was clearer than now, 2023, and I think it can have a historical value. Now I'm living in Romania with 3 cats as an independent data scientist.
Actually, nothing has progressed in the plant since 2011. We still don't even know what is going on inside. They must keep cooling the crippled reactors by water, but additionally groundwater keeps flowing into the reactor buildings from the broken parts. This is why highly contaminated water is always produced more than it can circulate. Tepco is planning to officially discharge this water to the Pacific but Tritium is still remaining in it. They dilute this with seawater so that it is legally safe, but scientifically the same amount of radioactive tritium is contained. They say it is safe to discharge, but none of them have drunk it.


November 2014